Guide for pneumatic tire treads



June 10," 1930.

C. E. MAYNARD GUIDE FOR PNEUMATIC TIRE TREADS Filed Oct. 24; 1927 IIIIIII/IIIIIIIIIIIi;;;IIIIIIIIIII/IIIIII INVENTOR.

V Patented Jun e 1 0, 1930 i r 7 UNITED STATE FISK RUBBER COMPANY, OF OF MASSACHUSETTS CHARLES EDGAR Minimum, or NORTHAMPTON, mafssnorrusnrirs'nssrenon To "run GUIDE FOR mEcMAT'I'c fr itnftrnn ans Application filedbctober 24, 1927. Serial 1%, 228,153.

'In the manufacture of pneumatic tires difficulty is often found in centralizing the tread portion of the tire upon the tire-carthe center of the tread is used in conjunction with my guide for centralizing the tread V smoothly over a tire carcass. Another object is to provide a guide that will stretch a I tread'at its heavy center section as it is drawn onto a tire carcass.

*In' the'drawings I have shown a guide made in I accordance with invention, adapted to be used on a machine, of the type known asa flat bandtire building machine.

However, I do not limit myself to guides for this type of machine as with but slight alteration, in which the principle of the invenr tion is not changed, these guides could be adapted for use with .other tire machines.

Referring to the drawings,

Fig. 1 is a side elevation ofa'tire building machine, partially broken away, showing the location of a guide on the machine;

' Fig. 2 is a plan view of Fig. 1;

- vention.

linelel of Fig.3;1andj. 7

v Fig. 3 is a view, partly in'section, taken on line 3-3 of'Fig. 1; I 7

Fig. 4 is a view taken substantially on Fig. 5 is a view line 5 5 of Fig. 3. I

- In the drawings, a-tire buildingmachine 10 having a collapsible drum 11 is shown taken on equipped with a device embodying my in-' The device is made up of two separate units, a shelf 12 and a guiding unit The shelf '12, pivoted at 14 to the machine 10 and projecting over the drum 11 when being used, is adapted to. swing out of its operative; position in which itv lies against a stop 15 intoan inoperative positioniagainst a's'top 16, as indicated by, dotted lines'at 17., The shelf 12 has-on itssldes'at equal dis-,

tances from the. centerof the drum 11 a pair of; bars 18] with projections -19 adapted; to align the shelf. .j

. The ;other of -the devicefthe guiding: unit 13, is adapted to fit overthe bars 18 and a tiretread20xbeing drawn overthe shelf 11..

onicornn minus MAssAcnvs irrs, n' conronn'rron guidingunit-13 squarely over the Apairofme nbers 21 onthe guiding unit 13 are threaded to .an adj usting screw .22 .at.

equaldistances from the center of the. unit.

The center; of: the unit. is located just above the center-cftheibuilding drum ll'due to a. j

pair; of downturning flanges. 23 on the. unit fitting over the bars 18., -The screwf22 is housed in bearings 24 at each end, a projection 25 through one bearing beingmilled to. provide means whereby the screw may be turned, Thisscrewhason onejside of its;

center portion a left hand thread and on the t otherlside a. right handthread .causing the members 21 L to either move 1 simultaneously toward .or. away from each other when the 1 screw is turned; The members 21 will therej fore alwaysbeat ,equal.distanc.e s from the.

center of the unit enabling-the use of the de-f vice for treads ;ofvarious. widths. "These members are formed on their guidingsur-i,

faces 26v to the contour of the heavyportion ofthe tread. v

In operation, the shelf 12 is pivoted from its inoperative position against the stop 16 around to the stop 15. The tread'is laid over the shelf and over a convenient supporting roll 27. The guide unit 13 is placed on the tread so that fianges'23 on the unit will fit over the bars 18 and against the projections 19. e The unit is now centralized in relation.

to the drum 1-1 on which a tire carcass 28 has already been built. As the unit 13 does not rest directly. on the shelf 12 but is only guided b-ythe flanges 23 andthe bars 18 to,

prevent sideward motion of the unit the tire builderCmay press downon the unit, this pressing the thread 20 to the shelf. As the tread now is drawn off the shelf 12 onto'the carcass 28 it will belstretched at its heavy center portion due to the pressure given the guide unit 13 by the operator. This will cause the tread to lie smoothly and centrally on the, carcass Without any undue stretching andzwrinkling of the thin side portions of the tread. Having thus described my invention, I

ai i a 1; In a tire building machine,- a devicefor a 10 centralizing atire tread on atire carcass comprising in combination a shelf projecting over the tire carcass and an adjustable. guide pressing a tire tread on the shelf as the said tread slides over it. v l

' 2. In a tire building machine, a tread guiding device presenting a confinedv guiding passage for the shouldered central portion of a tread and an unconfined support for the outstanding relatively thin sides of the tread 3. In a tire building machine, a tread guiding device presenting a confined guiding: passage for the shouldered central portion of a tread,the passage being contractible in'a direct-ion normal to the tread surface for 265 exerting tension to the tread.

{L In a tire'building machine, a tread guiding device presenting a confinedguiding passage for the shouldered centralportion of a tread, the passage being contractible me 319 direction normal to thetread surface for exerting tension to the tread, and an unconfined support" for the outstanding relatively: thinsides ofthe tread. v

51 111 tire building machine, a tread V guiding device presenting a-flat'surfaceover which a tread may pass and guiding-surfaces acting upon intermediate shoulders of the tread. w

In autire buildinginachine a device for 46 guidii'ig' a tire tread centrally and smoothly over a tire carcass on'the machine consisting of a shelf centralized over the tire carcass and a guiding unit fitting centrally'onthe shelf and adapted toiha've attire tread pass between the said guidingiunit and the shelf.

7 CHARLES EDGAR: MAYNARD. 

